Art of stenciling



March 18, 1941. J. E. DUGGAN ART OF STENCILING Filed April 14, 1939 FIG.2.

INVENT-OR. JAMES E. DUGGAN v \2,-,%-5,W

ATTORNEYS Patented Mar. 18, 1941 UNITED STATES PATNT QFFICE ART OF STENCILING Michigan Application April 14, 1939, Serial No. 267,843

1 Claim.

The present invention relates to stencils and methods of and means for stenciling,

Heretofore, in stenciling operations, where the stencil involved closed figures or letters like the letter 0, it has been customary to use either a cut stencil in which the center is supported by pieces of material not cut out or to use a silk stencil in which the masking portions have been rendered impervious to the paint or other coating material.

Both of these methods are open'to objection. The first produces a letter which shows the marks of the bridge pieces, and the second produces in a great many instances letters of which the edges are uneven. In the latter case, too, the stencils are easily damaged and expensive and diflicult to make.

The present invention has among its objects the elimination of many of the objections heretofore encountered and the provision of a metal stencil which may in most instances be substituted for the silk stencil and be less expensive to make and more satisfactory in use.

Another object is a method of and means for using such stencils.

Another object is a substantially continuous process of stenciling.

Still other objects will readily occur to those skilled in the art upon reference to the following description and the accompanying drawing, in which:

Figure l is a more or less diagrammatic perspective View of the chief parts of the machine.

Figure 2 is a perspective view showing a section of a stencil in place. I

' Figure 3 is a sectional view of a stencil.

Figures 4 and 5 are respectively a plan view and section of a portion of one form of stencil.

Figures 6 and 7 are similar views of a slightly modified form.

In the drawing, the stencil 20 is shown as circular and dished but it should be understood that it may be of any form or shape to fit snugly over the object to be stenciled. In the present showing, the object itself, 2|, is circular and dished and will be referred to as a plate.

In those cases where the letters or figures or other characters or designs are closed, as in the case of the A and D shown, the cut out central area of the character is accurately located and maintained in place by a highly arched bridge piece 22, preferably of fiat relatively thin material, so that when the stenciling coating material is applied by spraying, or in any other 55 suitable fashion it will float easily under the which the bridge 22a is shown as a wire or round rod.

Both forms of the stencil and stencils of any other shape or configuration as contemplated by the present invention are to be made of magnetic material, such as steel.

Figure 1 shows diagrammatically a method of continuous operation in stenciling small parts.

In this figure, a conveyor belt 3i) is shown as having hinged to one edge a plurality of stencils 29 and to pass overthe surface of a magnet 3|. This latter may be of any suitable construction similar to the several conventional magnetic chucks and may be arranged to exert a continuous magnetic eifect.

The plates 2| will be suitably positioned upon the conveyor 30 and the stencil lowered upon it as they approach the magnet.

Upon reaching the magnetic influence, the stencil will be firmly held upon the plate as will also the small bridge-held piece, and, while the plate and stencil are passing over the magnet the coating material may be applied to them.

Since it is relatively easy to slide a magnetically held piece upon the face of the magnet the conveyor may be moved continuously or it may be halted temporarily,

The coating may be done while the part is over the magnet and therefore while the stencil is most firmly held.

After the part has moved beyond the magnet, it may pass on through a drying station with the stencil still in place but it is preferred to lift the stencil before completing the drying.

A suitable way of preparing stencils for the present process is to make a thin stamping of magnetic metal from the same dies as are used for the part and then rout out the design and apply the arched bridges to hold the severed pieces in proper location.

While the foregoing description relates more particularly to ordinary metal stampings as the parts being stenciled, it is obvious that a magnetic stencil may be held firmly in place upon any material itself magnetic or non-magnetic, metallic or non-metallic, such as steel, stainless steel, non-ferrous alloys, ceramics, etc.

Now having described and illustrated a preferred embodiment of the invention, what is claimed is:

The method of stenciling which comprises continuously moving an object to be stenciled toward, through and out of a magnetic field, applying a magnetic stencil to said object as it approaches said field whereby when in said field said stencil will be firmly held 'in place, and applying stencil coating thereto while in said'field.

JAMES E. DUGGAN. 

